@matheusbsbs / matheus-bagliano / commits / 96a9a3e42e

bundle: default to SHA1 when reading bundle headers

We hit a segfault when trying to open a bundle via `git bundle list-heads` when running outside of a repository. This is caused by c8aed5e8da (repository: stop setting SHA1 as the default object hash, 2024-05-07), which stopped setting the default object hash so that `the_hash_algo` is a `NULL` pointer when running outside of any repo. This is only a symptom of a deeper issue though. Bundles default to the SHA1 object format unless they advertise an "@object-format=" header. Consequently, it has been wrong in the first place to use the object format used by the current repository when parsing bundles. The consequence is that trying to open a bundle that uses a different object hash than the current repository will fail: $ git bundle list-heads sha1.bundle error: unrecognized header: ee4b540943284700a32591ad09f7e15bdeb2a10c HEAD (45) Fix the bug by defaulting to the SHA1 object hash. We already handle the "@object-format=" header as expected, so we don't need to adapt this part. Helped-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Patrick Steinhardt committed Aug 13, 2024 at 11:18 UTC 96a9a3e42e85874ba5edfcf86d91f7d8c05d5f94

2 files changed +31 -1

bundle.c

+6 -1

@@ -89,7 +89,12 @@ int read_bundle_header_fd(int fd, struct bundle_header *header,

89 goto abort;

90 }

92 - header->hash_algo = the_hash_algo;

92 + /*

93 + * The default hash format for bundles is SHA1, unless told otherwise

94 + * by an "object-format=" capability, which is being handled in

95 + * `parse_capability()`.

96 + */

97 + header->hash_algo = &hash_algos[GIT_HASH_SHA1];

99 /* The bundle header ends with an empty line */

100 while (!strbuf_getwholeline_fd(&buf, fd, '\n') &&

t/t6020-bundle-misc.sh

+25

@@ -659,4 +659,29 @@ test_expect_success 'unbundle outside of a repository' '

659 test_cmp expect err

660 '

661

662 +test_expect_success 'list-heads outside of a repository' '

663 + git bundle create some.bundle HEAD &&

664 + cat >expect <<-EOF &&

665 + $(git rev-parse HEAD) HEAD

666 + EOF

667 + nongit git bundle list-heads "$(pwd)/some.bundle" >actual &&

668 + test_cmp expect actual

669 +'

670 +

671 +for hash in sha1 sha256

672 +do

673 + test_expect_success "list-heads with bundle using $hash" '

674 + test_when_finished "rm -rf hash" &&

675 + git init --object-format=$hash hash &&

676 + test_commit -C hash initial &&

677 + git -C hash bundle create hash.bundle HEAD &&

678 +

679 + cat >expect <<-EOF &&

680 + $(git -C hash rev-parse HEAD) HEAD

681 + EOF

682 + git bundle list-heads hash/hash.bundle >actual &&

683 + test_cmp expect actual

684 + '

685 +done

686 +

687 test_done